ComparativeIn VitroBinding Studies of TiCl₂(dpme)₂, Ti(ada)₂(bzac)₂, and TiCl₂(bzac)(bpme) Titanium Complexes with Calf-Thymus DNA

Abstract

The binding of TiCl2(dpme)2 (1), (dpme = 6,6′-dimethyl-2,2′-bipyridine), Ti(ada)2(bzac)2 (2), (ada = adamantylamine; bzac = benzoylacetone), and TiCl2(bzac)(bpme) (3), (bpme = 4,4′-dimethyl-2,2′-bipyrdine) with calf thymus (ct) DNA has been studied by UV-visible spectroscopy, thermal denaturation, and circular dichroism spectroscopy. In UV-visible study complexes 1, 2, and 3 showed red, blue, and red shifts, respectively, upon the addition of ct-DNA along with a significant hyperchromism. The intrinsic binding constants (K b) calculated from UV-visible absorption studies were 2.3 × 103 M−1, 3.3 × 103 M−1 and, 7.1 × 103 M−1 for complexes 1, 2, and 3, respectively. The change in melting temperature (ΔT m) was calculated to be 2-3°C for each complex. Circular dichroism (CD) study showed blue shift for complex 2 and red shift for complexes 1 and 3 along with rise in molecular ellipticity upon the addition of complexes. Results suggest a binding mode of complex 2 different than 1 and 3.

Synthesis, characterization and separation of chiral and achiral diastereomers of Schiff base Pd(II) complex: A comparative study of their DNA- and HSA-binding

“…While a groove binding or electrostatic interaction leads to hyperchromic effect along with blue shift [43]. A hyperchromic effect can be due to breakage of the secondary structure of DNA [44], [45].…”

Spectroscopic Studies of the Binding Interactions of Phenothiazininum Dyes (Thionine Acetate, Azure A and Azure B) with Calf-thymus DNA

“…Circular dichroism spectra of ctDNA (1 × 10 -4 M) was recorded in the presence of increasing amounts of dye at the following stoichiometric ratios: r The CD spectrum of ctDNA consisted of a positive peak at 275 nm and a negative peak at 244 nm, which is characteristic of B-form of DNA. An increase in the positive peak at 275 nm is observed on addition of dye to it, which is in turn result of intercalation of dye into the DNA base pairs [39]. An increment in the intensity at 245 nm has also been noticed, giving an indication of stabilization in the righthanded more compact B-form of DNA [40].…”

Synergy Between DFT Calculations and Experimental Studies on the Optimized Structures and the Antibacterial Potential of Some Novel Tetra‐ and Penta Coordinated Organic‐ Inorganic Hybrid Complexes of Titanium(IV)

“…The structure of titanium(IV) complexes may be modified by assembly of various organic ligands around the central titanium atom. The biological activity of titanium(IV) complexes may be effected by a number of factors such as nature of organic ligands, [18] coordination number of titanium [13] and geometry of complexes. [19] Titanium(IV) complexes derived from sterically demanding and sterically undemanding organic ligands constitute an important and interesting area of research.…”